The goal of this research study was to develop a music therapy tool using a computer-generated harp which could provide users with visual, audio, and haptic feedback during interaction with the virtual instrument. Realistic 3D visual and haptic feedback was provided through immersion in a portable augmented reality-based system composed of a video see-through head mounted display (HMD) and a Sensable Phantom Omni haptic device. Users play the virtual harp by using the Phantom Omni haptic device to pluck or strum the strings of the harp. Users can also freely move the harp in the augmented reality environment to provide a more realistic experience, similar to that of playing a traditional musical instrument. The system will be used to provide interactive musical experiences and to develop motor skills among individuals with disabilities through music therapy. A virtual therapist feature was developed which can be used by a therapist without musical knowledge to observe a user during therapy exercises or by a user to engage in self-motivated therapy exercises outside the therapy room. With the virtual therapy feature, users can follow a simple pre-determined sequence of notes using color-coded strings. User testing was completed to study usability, therapeutic effectiveness, and patients’ therapy motivation.